We're not yet suffering from famine, because new technologies allowed us to extract way more food than anticipated from the same surface area. However, these practices are not workable long term. You can't actually extract the amount of food we are currently extracting from our agricultural land for another 100-200 years. If we try, we'll ultimately leave the soil in such a bad state that will not grow much of anything - and mass starvation will happen long before then.